Many projects benefit from a small display as a user interface. For very low power applications this is usually a no-go as the display needs too much energy. I have used e-paper displays from Kent: while these e-paper displays do not need any power to keep the image, changing the display content is not for free, plus is very slow (around 1 second needed to update the display). So I was looking for something low power and fast for a long time, until Christian (thanks!) pointed me to a display from Sharp: both very low power and fast:

For many of my applications I need to measure a distance. I have used ultrasonic sensors, but there view angle (beam) is not able to detect smaller objects, it very much depends on the object surface and angle, it is slow and not very precise. I have used infrared sensors, but here again it depends on the infrared reflection of the object in range, it depends the amount of reflected light is not really telling much about the distance, and yet IR reflection is subject of material and object targeted.

But there is yet another sensor type to consider: ToF! ToF (or Time-of-Flight) sensors have a built-in LIDAR: The sensor is sending out light pulses and measures how much time it takes for the light to come back. Similar to ultrasonic sensors (see “Tutorial: Ultrasonic Ranging with the Freedom Board“), but instead of ultrasonic it uses an infrared laser light. Or think about a radar system using an infrared laser light.

Getting a board from a distributor like Farnell/Element14/Mouser (add your own distributor) means that chances are high that the default firmware on it is written years from now because the inventory has not been updated, or because boards are still produced with that original firmware (because of testing?). So what happens if I use board with a firmware developed pre-Windows 8/10 area?

Freshly Unboxed NXP FRDM-KL25Z Board

It might work, but chances are high that the bootloader and firmware is not ready for the ‘modern age’, and as a result the board might be bricked. If you still have a Windows 7 machine around (I do!), you are lucky. If not, then you need to read this article….

One goal of this blog is to inspire engineers, in one way or another. And when I get reports back that things were useful, I like to share it :-).

So here is something what a team of young undergraduates (Przemyslaw Brudny, Marek Ulita, Maciej Olejnik) did for theirs Master Thesis work at the Politechnika Wroclawska, Poland: a very cool flying machine controlled by two Kinetis K66, having many sensors (on own designed boards) with a custom debug/programmer board similar to the tinyK20, developed with the NXP Kinetis Design Studio:

To put the tinyK20 board with the NXP Kinetis K20 into bootloader mode, well someone could check the schematics, or follow this quick guide :-). In short, the pin PTB1 has to be pulled to Ground (GND) while powering the Kinetis K20. The pin PTB1 is on the outside row as below:

In “openHAB RGB LED Light Cube with WS2812B and NXP Kinetis” I started experimenting Kinetis boards, a LED cube diffuser and Adafruit WS2812B NeoPixel LEDs. That worked well, but I was not to very happy about the visual effect. So here is my next version: I wanted to have control over each side of the cube. For this I have built a cube inside the cube with a 3D printed structure:

Sometimes it is all about doing fun stuff: to carry and store the tinyK20 (NXP/Freescale Kinetis K20) boards needed for next course, I wanted to build something geeky: a MUFG capsule to store and duplicate Kinetis boards 🙂

The reset and signal line of a microcontroller is probably the most important signal to a microcontroller. And if things go wrong, then a first thing to check is the reset line. So having control over reset is an important aspect for embedded development. You would think that if you download a program to a microcontroller, the debug probe would put the device into reset at the start with a short pulse like this:

The tinyK20 boards are now used in several projects. Initially I was considering a commercial USB thumb drive enclosure for it. But this needed some tweaking of the enclosure so at the end it was not ideal. 3D printing is probably that hot topic for 2016. So why 3D printing an enclosure for that board?

For a research project we would like to use the tinyK20 to log gyro sensor data. For this I have created a quick-n-dirty project to explore how feasible it is. The tinyK20 has all the pins on the outside of the board, so I’m able to put it on a bread board: